diff --git a/ChangeLog b/ChangeLog
index 1453b9e76a..96a2e6c143 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jan 29 03:49:36 2014  Aaron Patterson <aaron@tenderlovemaking.com>
+
+	* ext/fiddle/closure.c: use sizeof(*pcl) for correct sizeof value.
+	  [ruby-core:57599] [Bug #8978].  Thanks mame!
+
 Wed Jan 29 03:36:42 2014  Eric Wong <e@80x24.org>
 
 	* doc/contributing.rdoc: allow/encourage other git hosts
diff --git a/ext/fiddle/closure.c b/ext/fiddle/closure.c
index 121a08ea19..cb0c462a08 100644
--- a/ext/fiddle/closure.c
+++ b/ext/fiddle/closure.c
@@ -234,7 +234,7 @@ initialize(int rbargc, VALUE argv[], VALUE self)
 #else
     result = ffi_prep_closure(pcl, cif, callback, (void *)self);
     cl->code = (void *)pcl;
-    i = mprotect(pcl, sizeof(pcl), PROT_READ | PROT_EXEC);
+    i = mprotect(pcl, sizeof(*pcl), PROT_READ | PROT_EXEC);
     if (i) {
 	rb_sys_fail("mprotect");
     }